Muzzle attachment for guns



March 14,, 19 39. S. G. GREEN 2,150,161-

MUZZLE ATTACHMENT FOR GUNS Filed Oct; 16, 1936 Inventor Samua13.l3reen E h W WZ Patented Mar 14, 1939 I umreo STATE-s PATENT oFFlcs 6 Claims.

(Granted under the act of March 3, 1888, as amended April 30, 1928; 370 G. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a muzzle attachmen for guns and more particularly it has reference to that class of attachments serving to check recoil, silence the report and conceal flash.

The principal object of this invention is to provide an inexpensive attachment which may be readily disassembled for cleaning and replacement, and will reduce the pressure progressively so as to eliminate a blasting efiect.

To these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claims forming a part of this specification.

A practical embodiment of the invention is illustrated in the accompanying drawing, where- Fig. 1 is a view in side elevation of the improved muzzle attachment applied to a gun.

Fig. 2 is a longitudinal sectional view.

Fig. 3 is a detail view of the inner front tube.

Fig. 4 is a sectional view on the line l-t of Fig. 2.

The attachment is conveniently formed of two parts comprising an imperforate rear outer tube 5 seourable to the muzzle of a gun barrel 6 as by a threaded engagement 1 and a front inner tube 8 inserted in the outer tube and having its rear portion in threaded engagement 9 with the outer tube and with its rear end Ill abutting a shoulder ll .of the outer tube. This connection between the inner and the outer tube is some distance forwardly of the muzzle of the gun barrel.

The inner tube has an external collar l2 in front of its threaded 'portion and this collar engages a shoulder l3 at the front end of the threads of the outer tube. The collar serves as a guide during insertion of the inner tube and blocks off the threads to'prevent them from being fouled by carbon. The portion of the inner tube in front of the collar I2 is spaced from the outer tube to provide an annular chamber l4 open at its front end. When assembled theinner tube projects from the outer tube.

The outer tube is formed with an expansion chamber l5 flaring from a point directly in front of the barrel and,terminating at the shoulder H where it meets the inside surface ofthe inner tube.

' chamber it in its rear po ion and a forwardly constricted chamber H in s front portion which terminates in a cylindrical outlet IS. The outer wall 89 of the chamber H is also tapered to provide a large outlet 20 for the annular chamber ill and it terminates or merges with a baffiing surface 28 which is perpendicular to the axis of the attachment and serves to deflect gases away from the outlet Q8. The front edge of the outer tube is positioned intermediate the length of the tapered outer wall i9.

The inner tube is prwided with a plurality of rows of apertures 22 progressively increasing in size from rear to front. When the gases flow through the attachment, a portion will be vented through the rear row of apertures and the pressure within the attachment will be accordingly reduced. Since the flow of gases through the apertures is governed by the pressure within the attachment and since the pressure is def creasing the next or middle row of apertures must be larger than the rear row in order to vent a larger amount of the gases. By virtue of this arrangement the reduction of the pressure within the attachment will be at a uniformly increasing rate. The front row of apertures are located at the beginning of the constricted chamber ll.

The combined volume. of the chambers i 5, l6 and I1 is approximately equal to the volume of. the gun barrel including the cartridge chamber. For the purpose of consuming the unburned powder and eliminating flash, the attachment has the effect of doublingthe length of the gun barrel, which relation appears to be the most beneficial. I have found that when the volume of the attachment is greater than the volume of the barrel an internal flashing or blasting effect is produced which will damage the parts.

The chambers l5 and I6 permit expansion of the gases and give time for burning. The constricted chamber I1 serves as a choke to furtherincrease the burning time in the chambers l5 and I6 and to increase the velocity of the balance of the gases which issue through the outlet l8. This increased velocity is obtained without back pressure and tends to choke flash.

' In order to secure the beneficial results just outlined the expansion chambers I5, l6, and the chambers i1 and I8 should preferably have a definite relation to'one another.

The chamber i5 should be between two and three caliber-s in length, the chamber l6 between four and five calibers, the chamber l1 between The inner tube has a cylindrical expansion three and one-half and four and one-half calihers and the chamber it about one one-half calibers.

The purpose in positioning the outlet or the chamber i i in rear of the outlet 68 and in deflecting the vented gases by the baiile ill is to prevent intermingling of the cooler gases from the chamber M with the gases of higher temperature and greater velocity that issue through the outlet l8. Intermingling of these gases produces reignition of the cooler gases and a resulting flash. This type of attachment is intended primarily for short burst firing where it. is desired to obtain an optimum temperature from 900 to 950 degrees in a minimum of time.

I claim:

1. A muzzle attachment for a gun comprising an outer tube securable to an element of a. gun,

.said tube having a conical forwardly flared wall forming a chamber, an inner tube secured to the outer tube forwardly of said chamber and spaced from the outer tube to provide'an annular chamher, the inner tube 'aving a cylindrical portion forming an expansion chamber in continuation of the flared chamber and a tapered contracted portion forming a chamber with an axial outlet, the cylindrical portion of the inner tube also having apertures increasing in size from rear to front and leading to the annular'chamber.

2. A muzzle attachment for a gun comprising an outer tube securable to an element of a gun,

' said tube having a conical forwardly flared wall forming a chamber, an inner tube secured to the outer tube forwardly of said chamber and spaced from the outer tube to provide an annular chamber, the inner tube having a cylindrical portion forming an expansion chamber in continuation of the flared chamber and a tapered contracted portion forming a chamber with an axial outlet, the inner tube also having apertures in its cylindrical portion leading to the annular chamber.

3. A muzzle attachment for a gun comprising an outer tube securable to an element of a gun, said tube having a wall forming a flared expansion cha rear portion for initially receiving gases of discharge, an tube secured to the outer tube and having a cylindrical por tion spaced therefrom over a large portion of its length to provide an annula chamber open at its of the wall forming the tapered contracted.

chamber to provide a forwardly enlarging outlet and means for venting gases through the wall forming the cylindrical expansion chamber of the attachment to the annular chamber.

5. In combination, a gun barrel, an attachment on the muzzle having a Wall forming from rear .to front a flared expansion chamber, a cylindrical expansion chamber, a tapered contraction chamber and an outlet chamber, the volume of said chambers being substantially equal to the volume of the gun barrel, and means for venting gases through the wall forming the cylindrical expansion chamber.

6. In combination, a gun barrel, an attachment on the muzzle having a wall forming from rear to front, a flared expansion chamber two to three calibers in length, a cylindrical expansion chamher four to five calibers in length, a tapered contraction chamber threeand one-half to four and one-half calibers in length, a cylindrical outlet chamber one and one-half calibers in length, and means for venting gases through the wall forming the cylindrical expansion chamber.

SAMUEL G. GREEN. 

